J/A+A/654/A40 NGC1042 g and r deep final images (Trujillo+, 2021)
Introducing the LBT Imaging of Galactic Halos and Tidal Structures (LIGHTS)
survey. A preview of the low surface brightness Universe to be unveiled by LSST.
Trujillo I., D'Onofrio M., Zaritsky D., Madrigal-Aguado A., Chamba N.,
Golini G., Akhlaghi M., Sharbaf Z., Infante-Sainz R., Roman J.,
Morales-Socorro C., Sand D.J., Martin G.
<Astron. Astrophys. 654, A40 (2021)>
=2021A&A...654A..40T 2021A&A...654A..40T (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Galaxies, optical ; Galaxies, photometry ;
Photometry, surface ; Photometry, ugriz ; Combined data
Keywords: galaxies: evolution - galaxies: formation - galaxies: halos -
galaxies: photometry - galaxies: structure - cosmology: dark matter
Abstract:
We present the first results of the LBT Imaging of Galaxy Haloes and
Tidal Structures (LIGHTS) survey. LIGHTS is an ongoing observational
campaign with the 2x8.4m Large Binocular Telescope (LBT) aiming to
explore the stellar haloes and the low surface brightness population
of satellites down to a depth of muV∼31mag/arcsec2 (3s in 10"x10"
boxes) of nearby galaxies. We simultaneously collected deep imaging in
the g and r Sloan filters using the Large Binocular Cameras (LBCs).
The resulting images are 60 times (i.e. 4.5mag) deeper than those from
the Sloan Digital Sky Survey (SDSS), and they have characteristics
comparable (in depth and spatial resolution) to the ones expected from
the future Legacy Survey of Space and Time (LSST). Here we show the
first results of our pilot programme targeting NGC1042 (an M33
analogue at a distance of 13.5Mpc) and its surroundings. The depth of
the images allowed us to detect an asymmetric stellar halo in the
outskirts of this galaxy whose mass (1.4±0.4x108M☉) is in
agreement with the Lambda Cold Dark Matter (LambdaCDM) expectations.
Additionally, we show that deep imaging from the LBT reveals low mass
satellites (a few times 105M☉) with very faint central surface
brightness muV(0)∼27mag/arcsec2(i.e. similar to Local Group dwarf
spheroidals, such as Andromeda XIV or Sextans, but at distances well
beyond the local volume). The depth and spatial resolution provided by
the LIGHTS survey open up a unique opportunity to explore the `missing
satellites' problem in a large variety of galaxies beyond our Local
Group down to masses where the difference between the theory and
observation (if any) should be significant.
Description:
There are the g and r deep final (coadded) images of the galaxy
NGC1042 produced by the LIGHTS team. These images were created after a
careful coaddition of 30 different pointings around the galaxy with
the aim of preserving the low surface brightness features around this
target. They correspond to a total on-source integration per filter of
1.5h taken by the 2x8.2m LBT telescope. The spatial resolution and
depth of these images should be equivalent to the ones expected to be
produced by the Vera Rubin observatory by the end of the LSST survey.
In this sense, they can be considered as a good test-bed case of the
data quality expected for this survey. Details about the reduction
procedure as well as the zeropoints of the data can be found in the
paper describing the reduction (arXiv:2109.07478).
Each fits file contains 2 extensions
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Column 1: Index (counting from 0, usable with `--hdu').
Column 2: Name (`EXTNAME' in FITS standard, usable with `--hdu').
Column 3: Image data type or `table' format (ASCII or binary).
Column 4: Size of data in HDU.
-----
EXT 0 n/a no-data 0
EXT 1 n/a float32 11001x11001
Objects:
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RA (2000) DE Designation(s)
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02 40 23.97 -08 26 00.7 NGC 1042 = LEDA 10122
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 113 2 List of fits images (updated files, 27-Jul-2022)
fits/* . 2 Individual fits images (updated files, 27-Jul-2022)
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 24 I5 --- Nx Number of pixels along X-axis
26- 30 I5 --- Ny Number of pixels along Y-axis
32- 54 A23 "datime" Obs.date Observation date
56- 61 I6 Kibyte size Size of FITS file
63- 82 A20 --- FileName Name of FITS file, in subdirectory fits
84-113 A30 --- Title Title of the FITS file
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Acknowledgements:
Ignacio Trujillo, trujillo(at)iac.es
History:
07-Oct-2021: on-line version
27-Jul-2022: corrected fits files
(End) Patricia Vannier [CDS] 24-Sep-2021